The present disclosure generally relates to power converters for wireless power transfer (WPT). More specifically, the present disclosure relates to power converters that may transmit power wirelessly and concurrently in two different frequency bands.
Recent developments in WPT technologies have incited an era of cordless charging in applications from consumer electronics to electrical vehicles. The advantages of the wireless charging for consumer electronics include a more convenient experience than plug-in charging, avoiding charging wires, and seamless charging to extend battery life. The latter is particularly important when considering the rapid advancement of high performance processors and displays, and the resulting increase in power demand.
One problem in the wireless charging realm is the lack of a universal standard. On one hand, the Wireless Power Consortium's Qi standard specifies a transmission frequency in the 87 kHz to 205 kHz range. On the other hand, the AirFuel Alliance, a merger between Alliance for Wireless Power (A4WP) and Power Matters Alliance (PMA) standards, employs the Industrial, Scientific, and Medical (ISM) frequency band within 6.78 MHz±15 kHz, and a low frequency band of 100 kHz to 300 kHz. Such standard segmentation results in inconvenience for consumers and manufacturers. Devices with wireless charging capability designed to different standards are not interoperable, potentially requiring users with multiple mobile electronic devices to purchase and maintain one charger per device.
Therefore, the inventors recognized a need in the art for a WPT transmitter that operates in multiple frequency bands, across multiple WPT standards.